Thoughts from a combined Apple/Linux/Windows geek.

I recently upgraded a couple of my machines from Ubuntu MATE 16.04 to 18.04. On both of them, I noticed that after the upgrade, the login window did not look correct. There was no background image. It didn’t look like a fresh 18.04 install. Plus, any changes I did in the Administration -> Login Window program didn’t take effect. I did some digging, and figured out what was going on.

Sometime between 16.04 and 18.04 (it appears that this happened starting in 17.10), Ubuntu MATE decided to stop using lightdm-gtk-greeter, and instead switched to using slick-greeter. It seems to be that on update installs, lightdm-gtk-greeter is not being removed, so it’s defaulting to using it rather than slick-greeter.

I was able to solve this very easily by running the following command: